An allograft includes bone or other tissues transplanted from one person to another. Allografts are used in a variety of medical treatments, such as knee replacements, bone grafts, spinal fusions, eye surgery, and skin grafts for the severely burned. Allografts come from voluntarily donated human tissue obtained from donor-derived, living-related, or living-unrelated donors.
Allograft processing centers are generally responsible for processing and cataloging allografts collected by organ procurement organizations (“OPOs”). The OPOs are, in turn, responsible for collecting and/or recovering voluntarily donated tissues and gathering any pertinent medical information about those tissues before transferring them to the processing center.
Once an allograft is received, the allograft processing center is then responsible for processing the allograft and readying it for safe and effective medical use. Such processing may involve several steps including inspection, testing, cleansing, and cataloging.
When allografts involve the knee joint, processing centers are often called upon by surgeons performing the tissue transplants to provide allografts with specific physical characteristics pertaining to the trochlea region of the distal femur. Specifically, and as shown in FIG. 1, the Patella bone rides in the trochlea groove located in the trochlea region of the distal femur during normal movement of the knee joint. Because the trochlea groove varies in size and shape from person to person, proper matching between the trochlea groove and the Patella is required for proper movement of the knee joint upon a transplant involving allograft tissue of either the upper femur or the Patella. As a result, medical professionals such as allograft processing technicians, tissue bank technicians, and/or surgeons are often called upon to measure the trochlea or sulcus angle (hereinafter the “trochlea angle”), denoted by angle A-B-C in FIG. 1. This type of measurement may then be documented and cataloged during allograft production and processing, thereby allowing reliable, proper matching between the donor allograft and the receiving patient.
Currently, two primary measurement methods are used to measure the trochlea angle. Both techniques present significant accuracy, repeatability, and usability challenges. First, a preparing technician or other medical professional may measure the rise and run of the trochlea groove and mathematically calculate the trochlea angle. Depending on the shape of the trochlea groove, a correct rise-and-run measurement and subsequent angle calculation may require multiple measurements, coupled with time-consuming calculations that require additional instrumentation, such as a calculator, to be present during allograft processing.
A second existing measurement technique involves employing a straight edge and a protractor to directly measure the trochlea angle. This method requires more than one piece of equipment and, due to the mismatched shape of a protractor as compared to the three-dimensional trochlea groove, provides an unwieldy and often inaccurate measurement.
Both of these existing techniques introduce opportunities for human error into the measurement process and present sterilization challenges in that the required equipment cannot be easily sterilized after each use or reasonably purchased and stored in bulk such that individual items may be collected after a single use and sent out for sterilization at regular intervals. As a result, there is a need for an efficient, repeatable, and sterile method of measuring the trochlea angle during allograft preparation and on living patients undergoing a medical procedure.